Trigeminal neuralgia (also called tic douloureux)is a very painful condition which typically causes electric shock-like pain in one or more branches of the trigeminal nerve, usually on one side of the face. The first branch of the trigeminal nerve provides sensation to the upper third of the face (forehead and the eyes), the second supplies the middle part and the third one the bottom third (lower jaw). Pain is usually very brief but is so intense that makes people wince and interrupts talking and eating. These electric shocks can occur many times daily and can be very debilitating, if left untreated.

Migraine can also involve part of the face on one side but the quality of pain is different – it is not as intense or brief. However, it is the same trigeminal nerve that transmits pain sensation in migraine as well.

The disturbance in trigeminal neuralgia is localized to the nerve itself after it exits the brain, while migraine originates in the brain and then involves fibers of the trigeminal nerve. There have been a few reports of migraine-tic where patients have both the electric shock-like sensation and persistent headache with nausea and other migraine symptoms.

Paroxysmal hemicrania and cluster headaches are sometimes misdiagnosed as trigeminal neuralgia because those two condition often cause excruciating pain around the eye.